Conventionally, a copper-iron type stabilizer has been mainstream as a high-intensity discharge lamp lighting apparatus for lighting a high-intensity discharge lamp (hereinafter, simply referred to as “discharge lamp” or “HID lamp”). However, an electronic ballast is recently becoming mainstream which uses a large number of electronic components with the aim of size and weight reduction as well as a function increase of a stabilizer. This electronic ballast is briefly described below.
A direct-current (DC) power source circuit section including a rectification circuit is connected to an alternating-current (AC) power source. A power conversion circuit section capable of adjusting and controlling a supply power to a discharge lamp is connected to the output end of the DC power source circuit section. Further, the discharge lamp is connected to the output end of the power conversion circuit section. The power conversion circuit section comprises: an inverter circuit section for converting an output of the DC power source circuit section into an AC voltage of a low frequency to be supplied to the discharge lamp and comprises a lighting control circuit section for controlling an operation of the inverter circuit section according to a state of the discharge lamp.
As for the conventional high-intensity discharge lamp lighting apparatus as described above, when HID lamps with different characteristics are to be lighted, it has been necessary to use high-intensity discharge lamp lighting apparatuses applying to the respective lamps intended to be lighted. Namely, it has been necessary to set high-intensity discharge lamp lighting apparatuses exclusively for the respective discharge lamps with different characteristics, which results in incurring a great deal of investment in terms of development cost, development term, and the like. For such a reason, the high-intensity discharge lamp lighting apparatus has been desired to have a performance capable of lighting a plural types of HID lamps.
Japanese Patent Laid-Open No. 2003-229289 proposes a high-intensity discharge lamp lighting apparatus adapted to light a plural types of HID lamps, introducing a means of integrating a time until the HID lamps exceed a prescribed threshold to discriminate the types of HID lamps as loads, and a means of giving a transitional change from the lighting apparatus to the HID lamps after the HID lamps reach the stable lighting state to detect transitional responses of the loads so as to discriminate the load types.
FIG. 54 shows a block diagram of the conventional example disclosed in Japanese Patent Laid-Open No. 2003-229289. In this figure, the apparatus comprises; a DC power source 111; a power conversion circuit 112 for converting a power from the DC power source 111 to supply the power to a high-intensity discharge lamp DL; a lighting control circuit 114 for controlling the supply power of the power conversion circuit 112; a detection means 115 of detecting that an electric characteristic, an optical characteristic or a temperature characteristic of the high-intensity discharge lamp after turning-on of the DC power source has exceeded a prescribed threshold; a timer means 116 of integrating the time until the characteristic exceeds the prescribed threshold; and a discrimination means 117 of discriminating the types of high-intensity discharge lamps according to the lengths of the integrated time obtained by the timer means 116. With such a configuration, the discharge lamp lighting apparatus and a luminaire are provided, wherein the apparatus is capable of discriminating a plurality of high-intensity discharge lamps with different rated power and lighting those high-intensity discharge lamps with the respective rated power.
As described above, the load objects of the lighting apparatus of Japanese Patent Laid-Open No. 2003-229289 are HID lamps with a plurality of types of rated power, and this lighting apparatus discriminates the types of loads according to transient characteristics or steady characteristics of the HID lamps when lighted, thereby to light any of the HID lamps at a rating. This makes it possible to use the HID lamps with different rated power with one lighting apparatus. There are therefore advantages as follows. For example, the HID lamp is easily switched to one with a lower rated power than normal for the purpose of energy saving. Further, when an optical design is to be changed due to renovation of a store or the like, what is required is just replacement of the HID lamp.
Further, foregoing Japanese Patent Laid-Open No. 2003-229289 proposes measurement of the time until the transient characteristic exceeds a prescribed value as a means of discriminating the loads, and proposes modification of the time in restarting. Here, the time is corrected in restarting because the startup in restarting is faster than that as an initial start characteristic.